Ectosperma clavata Vauch. Hist, des Conf. d’Eau douce, p.
34. pi. iii. fig. 10.; V. Ungeri, M, G. Thuret, in Annales
des Sciences Naturelles; Berk. Glean, Alg. t. 10.;
Harvey, in Manual, p. 149.
So far from agreeing with M. G. Thuret as to the propriety
of referring all other species of Vaucherim to this one,
and constituting a single species of the whole under the
name of Vaucheria Ungeri, I am of opinion that V. clavata
itself ought not to be regarded as a distinct species, but
merely as a condition of almost any one of the numerous well-
defined species Avhich have been described. I am led to entertain
this opinion from having repeatedly observed that
the club-shaped extremities are present, terminating many
of the filaments of almost aU the species which are now
recorded, and the distinctness of which cannot for a single
moment be doubted. True it is that very many specimens
covered with capsules do not present the club-form dilatations
of the filaments, and also that these latter are generally present
when the former are altogether wanting. But these facts
admit of a rational and interesting explanation, entirely consistent
with the view here expressed. The specimens of
Vaucheria furnished with capsules, and those having them
not, but possessing the claviform filaments, are usually met
Avith under very different circumstances, the one for the
most part in still Avater, and the other in floAving, such as
streams and cascades, that is, the one set of specimens are
found in circumstances favourable for the developement of
capsules and anther®, and for permitting the mutual influence,
Avhich these organs are supposed to exert on each
other, to take place ; and the other kind, or second set, are
encountered in localities most unfavourable for these purposes
and ends, and in which in many cases it Avould be Impossible
for capsules to develope themselves, the filaments being constantly
washed and pressed upon by the force and weight of
the incumbent and floAving waters. This leads to a necessity
on the part of Nature, who is so fertile in resources in times
of difficulty and danger, to adopt some other mode of reproductlon
for plants so circumstanced, and thus effectually to
guard against the extinction of the species — her great care.
This she beautifully and securely effects by ordaining that
the reproductive bodies should appear at the extremity of the
filaments, that is, in a situation where they are least or but
little exposed to the impetuosity of the stream or cascade
which may roll over them.
Vaucher remarks of th e species as folloAvs : — “ I t is met
w ith in the p u re and ru n n in g Avaters of fountains and rivulets,
and it attaches itse lf to the wood and stones which th e re are
found, and upon Avhich It forms tu fts o f a b rig h t green. I t
appears to be composed of tubes, Avhich are more slender th an
in the other species, and present likewise a more lustrous appearance
; it is soft and unctuous to th e to u c h ; its extremities,
principally in winter, are for th e most p a rt terminated w ith
oval and n o t a rticulated masses, o f which mention is made
above. T h e ir poAvder expands itse lf easily, especially when
one irrita te s th em with a n e e d le ; I Have vainly sought for
th e grains of th e p l a n t ; I have never been able to see them,
although th e species is very common, and I have sought for
them for two successive years.”
So far back as 1826, some interesting remarks were made
on this plant, or state of one, by M. Frank Unger, which
may not be deemed uninteresting. They are taken from
Charlesworth’s “ Magazine of Natural History.”
‘‘ I found,” says M. F ran k Unger, “ near Vienna in a
ditch containing some clear water, derived from the recent
melting of the snow, a Conferva, which, after cleansing from
the clay which surrounded it, I deposited in a Avine-glass
and placed in a window, where I could observe without disturbing
it. This was on the 5th of March, 1826. T avo days
afterwards I noticed the production of a crowd of new ramuli,
several lines in height, and rising from the general mass like
a fine green miniature sward. On the 9th, these filaments
produced fructification in the form of a darker green globule
at their summits, by Avhich I knew my plant to be the
Conferva dilatata. Cat. Bot. Roth., or the Ectosperma clavata
of Vaucher.